Technical Field
The disclosure relates in general to a manufacturing method of display with lighting devices, and more particularly to an arrangement method of lighting devices of a display.
Description of the Related Art
Electronic products with display panel, such as smart phones, tablets, notebooks, monitors, and TVs, have become indispensable necessities to modern people no matter in their work, study or entertainment. With a flourishing development of the portable electronic products, the consumers have higher expects on the functions, the specifications and the prices of the products. The development of next-generation display focuses on the energy saving and environment-friendly techniques.
Different displaying techniques have been well-developed. For example, liquid crystal display (LCD) has several advantages of lightweight, compactness, portability and low price, which has replaced the CRT monitors and becomes one of the most commonly-used displays in the electronic products. Besides LCD displaying technique, the displaying techniques also include the organic light-emitting diode (OLED) displaying technique and the micro-LED displaying technique. In the OLED displaying technique, the organic material thin film (ex: an emissive electroluminescent layer) and the glass substrate are adopted. When an electric current passes through the emissive electroluminescent layer, the emissive electroluminescent layer emits light in response to the electric current; thus, no backlight is required in the OLED display. Compared to the LCD, the OLED display without a backlight saves more energy, and is lighter and thinner. However, the life span of an OLED display is less, compared to LCD (ex: due to the short life span of the blue organic material). Also, making a large size OLED display is considerably more challenging than LCD. The micro-LED displaying technique drives an array of addressed micro-LEDs, and possesses several advantages such as power-saving, simple construction, small volume, thin outline package, high brightness, high reliability and high speed of response, etc. Moreover, the stability of materials and the life span of the micro-LED display are better than that of the OLED display. The micro-LED display would be more competitive than the OLED display in the future, wherein the micro-LEDs are mounted on the array substrate (known as “LED on array”). In the current manufacturing method, the micro-LEDs are formed and diced into several micro-LED chips (i.e. micro-lighting devices). The driving circuits and related traces are formed on the glass substrate to provide an array substrate (ex: TFT array substrate), and the micro-LED chips are then mounted on the array substrate. Afterwards, the electrical connection between the array substrate and an external controlling circuit is accomplished, followed by packaging process. The conventional method for disposing the micro-LEDs uses pick-and-place for assembly. However, there are hundreds of thousands sub-pixels or couple million sub-pixels of a display, the pick-and-place method is very time-consuming, which is definitely not suitable for massive production. Also, it is unlikely to apply the pick-and-place method for mounting the micro-LEDs on to a display with ultra-high resolution (ex: a display with 2K/4K resolution has 25 million sub-pixels).